**Acknowledgements**

*Protected Areas, National Parks and Sustainable Future*

health of the environment.

and materials, for example.

**2. Conclusions**

of hosts. Moreover, the laboratory diagnoses on the fecal samples enabled indirect partial analysis on the park ecosystem, being these stages of the parasites usually

Gastrointestinal parasite infections can determine weight loss, metabolic imbalance, reproductive problems, anemia, and dehydration. In severe cases, they may also cause fetal malformations, locomotor lesions, and even death of the animal [43, 44]. Due to the clinical manifestations of gastrointestinal parasites, many hosts present behavioral and functional changes within their community. A predator at the top of the food chain, for example, may exhibit a decrease in food intake and activity, including hunting [35]. Furthermore, anthropic actions may result in the introduction of etiological agents, which in certain circumstances determine emerging infectious diseases in wild animal communities [45]. However, according to [46], populations of wild animals are generally in balance with their parasitological fauna. However, environmental changes, especially anthropogenic ones, can determine the introduction of new infective agents and even stress factors that destroy this equilibrium by inducing pathological situations. Parasites can be considered excellent bioindicators of environmental impacts [47]. In this way it becomes relevant to perform routine coproparasitological surveys with noninvasive samples collected in trails of conservation units in order to indirectly check the

The study of wild carnivores through the analysis of noninvasive samples allows

Therefore, the association of the results obtained from the identification of wild

or domestic carnivores that share habitats, sympatric species, and the investigation of gastrointestinal parasites in the noninvasive biological samples of these animals are fundamental for understanding the effects of possible diseases that can affect wildlife. Moreover, a constant research of the gastrointestinal parasites in conservation units and protected areas is extremely important to detect possible human interference through the presence of specific parasites or the introduction of parasite taxa not commonly reported in free-living wild animals by invasive host species or domestic animals. In addition, noninvasive sampling is fundamental for updating the records on the circulation of wild fauna in conservation units,

the identification of the animal species by different techniques, as well as their monitoring without the exposure of these animals to situations of risk, stress, or the use of chemical tranquilizers by the researchers to manipulate the animals. In addition, through the analysis of noninvasive samples, mainly feces, it is possible to detect structures of gastrointestinal parasites that may potentially be infecting these animals. It should be emphasized that this type of sampling causes minimal interference in the carnivores' habitat during the collection of the biological samples in the environment by the researchers. Besides that, noninvasive sampling is not detrimental to the ecological niche of these animals, cooperating to maintain the integrity of the fauna and where they live. This sampling strategy is mainly important when studying regions' considered biodiversity hotspots, such as Madagascar Island, which has a unique and a high richness of biodiversity, which includes more than 98 species of mammals [58]. It is also important to highlight that the approaches about the biodiversity conservation have changed over the years, which means that conservation strategies are needed since all the species have their own function and values in the ecosystem, but also because they play a role in providing benefits to people and to economy, known as ecosystem services, producing food

detected in free-living wild animals' samples, such as felids [42].

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The authors thank the Laboratory of Parasitology of the Fluminense Federal University, the Itatiaia National Park and its employees, the Laboratory of Toxoplasmosis and Other Protozoan Diseases of the Oswaldo Cruz Institute, and CAPES.
